Methods and apparatuses of the above-referenced type are well known. For example, a measuring rod extending through the cylinder head wall is moved with the piston, and the position of the rod is detected capacitively or resistively. It is also possible to drive an electro-optical sensing device from the piston rod through a transmission device. Such a method requires large free space and substantially structural expense. Other well known distance measuring methods are unsuited for the determination of the relative distance between the piston and cylinder head of the assembly because the necessary measuring devices are too sensitive. Excluded equipment, for example, includes forklifts with hydraulically operated lifting forks, earth-moving equipment with hydraulically adjustable shovels, hydraulically operated extrusion presses, and many other applications of piston and cylinder assemblies for which there is no satisfactory device to exactly determine the relative positioning.